JPS6284003A - Suspension herbicide composition for paddy field - Google Patents

Abstract

PURPOSE:The titled composition suitable for treatment before rice transplanting in watered paddy fields, containing a pyrazole compound and alpha-chloro-2',6'- diethyl-N-(n-butoxymethyl)acetanilide, etc., having a specific viscosity. CONSTITUTION:The titled composition containing a pyrazole compound shown by the formula (R is H or CH3; Z is p-toluenesulfonyl, phenacyl, etc.,) and alpha- chloro-2,6'-diethyl-N-(n-butoxymethyl)acetanilide or the acetanilide and 3-(2,4- dichloro-5-isopropoxyphenyl)-5-t-butyl-1,3,4-oxadiaz-ol-2-(3H)-one-one as active ingredients, having 250-30 centipoise viscosity. The composition can control almost all of a wide range of weeds in paddy fields growing after rice transplanting, is directly applied during operation of plowing and can be uniformly dispersed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a suspension herbicide composition for paddy fields, and more specifically, it provides a manufacturing technology for a herbicide composition suitable for pre-planting treatment of flooded paddy fields. be.

Conventionally, wetting agents, emulsions, granules, etc. have been the main formulations of herbicides for use in paddy fields before rice planting. In particular, when applying wettable powders and emulsions, they are generally diluted with water to a predetermined concentration and prepared as a spray solution, but the amount of spray solution is large and it is difficult to spray uniformly over the entire surface of the rice field. requires a great deal of effort, time and expense. This dot granule formulation can be applied directly as is, so it can be said to be a labor-saving formulation.

However, granules generally have a relatively small herbicide content of about 5 to 15%, and during granulation, inorganic carriers such as bentonite, clay, kaolin, and talc, and various binders and surfactants are used. Not only is this necessary, but the manufacturing costs for granulation, drying, sizing, etc. may be large, and
It tends to cause uneven spraying and is not necessarily suitable as a herbicide for pre-transplant treatment.

In recent years, for the production of paddy herbicides before rice planting, direct application emulsions have been developed as preparations that allow the emulsion stock solution to be directly sprayed without diluting it with water, with the aim of saving labor and increasing efficiency during spraying. (1% Publication No. 1@56-26641). This type of emulsion is an oxacyacin emulsion and an oxacyacin-butachlor mixed emulsion, and the emulsion stock solution is directly sprayed onto the flooded surface during plowing work before rice planting.

As explained in Japanese Patent Publication No. 56-26641, this emulsion rapidly spreads on the flooded surface, and then becomes an emulsified state and settles down to the paddy soil. The manufacturing technology for such emulsions involves dissolving the herbicide in a solvent such as xylene, toluuni, methylnaphthalene, etc.
(18℃), surface tension 38-55 dynes/
cm (20°C), water surface spreading force of 50°C or more (18°C), but in order to reduce the specific gravity, the solvent is mainly limited to xylene, toluene, etc., and the herbicide content is is less than 30% (mainly 20~
15% or less), and has the disadvantage that it is difficult to apply to herbicides that are difficult to dissolve in these solvents.

The inventors of the present invention have solved the above-mentioned drawbacks in the formulation technology, and have succeeded in applying the liquid formulation directly and uniformly without diluting it with water during puddling work before rice planting. The present invention was completed as a result of intensive research into a formulation that can simultaneously kill most of the many types of weeds that occur in the world.

That is, oxacyacin emulsion and oxacyacin-butachlor mixed emulsion exhibit high herbicidal effects on annual weeds such as wild grass, cyperus, cyperus, cyperus, azalea, and perennial weeds such as fireweed, pine beetle, and cyperus, but not on perennial weeds such as cypress, cyperus, and cyperus. Since it has no effect on broad-leaved weeds, it is not necessarily perfect as a herbicide for pre-planting rice planting.

To explain this point in more detail, these perennial broad-leaved weeds tend to increase nationwide, and with regard to Urikawa in particular, according to a survey conducted in 1981, the area where they occur is 37% on average nationwide, and 50% in areas west of the Tokai region. It has reached the point where it exceeds %. Therefore, in paddy fields where rice fields are often infested, systematic treatment with medium-term herbicides such as phenothiol/cymetrine agents, cymetrine/MCPB agents, etc. is required, and a situation is occurring in which the labor-saving effects of pre-planting treatment agents are greatly diminished.

Naproanilide (trade name: Urivest Granules), which was recently developed to deal with the increase in the occurrence of urikawa, is highly effective against urikawa, but it is not used as a pre-planting treatment because of the chemical damage to rice seedlings. I can't.

The present inventors have developed a treatment agent that does not have these drawbacks and can control most of the wide range of paddy weeds that occur after rice planting, and that can be applied directly during puddling work and can be evenly spread. A pyrazole compound represented by formula (I) (wherein R represents a hydrogen atom or a methyl group, and Z represents a p-toluenesulfonyl group, a phenacyl group, or a p-methylphenacyl group, respectively), and α-chloro- 21,6/-diethyl-N-(n-ptoxymethyl)acetanilide, (hereinafter referred to as butachlor) or it and 3-(2,4-dichloro-5-isopropoxyphenyl)-5-tert-butyl-1,3
, 4-Oquinacyazol-2-(3H)-one (hereinafter referred to as oxacyacin) is combined into a suspension preparation (referred to as a sol or flowable agent); To achieve the intended purpose, this formulation consists of a technology that imparts the property that when this formulation is applied directly to a flooded surface without being diluted with water, it is easily and uniformly dispersed in the flooded surface. This is what was created.

The compound represented by the general formula (1) (in the formula, R represents a hydrogen atom or a methyl group, and 2 represents a p-toluenesulfonyl group, a phenacyl group, or a p-methylphenacyl group, respectively),
It is a herbicide with a wide herbicidal spectrum, showing outstanding herbicidal effects on annual weeds such as Cyperus japonica, Japanese cyperus, azalea, and Kikashigusa, as well as perennial weeds such as Japanese cyperus, Japanese cyperus, Japanese cyperus, Japanese cyperus, Japanese cyperus, and Japanese cyperus. Since these compounds are solid at room temperature69 and have low solubility in organic solvents commonly used as emulsions, such as xylene, toluene, naphtha, etc., it is extremely difficult to produce practical emulsions.

The compound represented by the general formula (1) has already been developed in Japanese Patent Publication No. 54
-36648, 56-28885, JP-A-54-70
No. 269 and No. 57-72903, and preferred specific examples are shown below.

H.J.O. H30 Some of its physical property values are as follows.

In addition, butachlor and oxacyacin have a high herbicidal effect on annual weeds such as wild grass, cyperus, cyperus, cyperus, azalea, and perennial weeds such as firefly, cypress, and cyperus, but they also
It has the disadvantage that it has no effect on perennial broad-leaved weeds such as snails.

Some physical properties of these compounds are as follows.

Under these circumstances, the inventors of the present invention have conducted intensive studies on herbicides that can be sprayed as a undiluted solution from a container during puddling operations, and have developed a suspension of specific pyrazole compounds, butachlor, and oxacyacin. This herbicide composition can be applied uniformly enough for practical use in flooded paddy fields.

The present invention has been completed by exhibiting a stable herbicidal effect on most of the weeds in paddy fields in addition to broad-leaved weeds such as P. elegans.

On the other hand, suspended herbicide formulations, although not new, have been developed primarily as formulations for aerial spraying9, and there are no known examples of their use as pre-treatment agents for rice planting in flooded paddy fields. However, in order to directly apply the undiluted solution of the formulation and uniformly disperse it during plowing work in flooded paddy fields, it is necessary to solve the following formulation technical problems.

1) A solid pyrazole compound represented by the general formula (1) and a solid oxacyacin or a liquid butachlor can be used in a preparation as a mixed suspension system of solid fine particles (suspension) and solid fine particles (suspension), or ,
Stabilization as a mixed suspension emulsion system of solid fine particles (suspension>-liquid and fine particles (emulsion) (separation of oil layer or water layer and) - prevention of decaking), 2) Stabilization of the above-mentioned from the flooded water surface Imparting a formulation with the property of quickly dispersing a suspended system in water (improving natural dispersibility)
(The herbicide suspension formulation according to the present invention has a specific gravity of all target herbicide compounds greater than 1, and is an aqueous suspension formulation using water, which imparts water surface spreading ability. (It is difficult to do so).

As a result of conducting a wide range of experiments with these objectives in mind, we found that: (1) Suspension stabilization of solid particles and emulsion stabilization of liquid particles can be achieved by selecting and blending nonionic surfactants and anionic surfactants. (2) The viscosity of the suspension formulation should be 250 to 30 centipoise (2) to promote stabilization of the formulation using a water-soluble polymer but to ensure rapid dispersion in submerged water. Scraping speed 38.40sec *20℃), preferably 200~
40 centipoise (shear rate 38.405ec-”-
20°C), preferably 100 to 50 centipoise (
In order to suppress the sliding speed (38.40 sec" * 20°C) and (3) further promote the dispersibility of the turbid preparation in submerged water, the surface tension should be 45 dynes/cm or less, preferably 40 dynes/cm. The above objective was found by setting the value to be less than an.

That is, through this experiment, specific gravity, viscosity,
Surface tension was extensively studied. As an experimental method, a large petri dish with a diameter of 27 cm and a depth of 15 m is filled with 25°C tap water to a depth of 10 m and left to stand. Suspended composition 1d from a height of 10 strokes above the water surface near the center of the petri dish
was gently dropped with a pipette, and its spreadability on the water surface and natural dispersion into water were observed.

Even if the specific gravity, viscosity, and surface tension of this composition are changed, the spreadability on the water surface is extremely small and the composition is almost completely submerged in water. The property of this composition to naturally disperse while settling under the water surface was mainly dependent on the viscosity, and the difference in specific gravity did not have a significant effect. The lower the surface tension, the more it promotes natural dispersion, but its effect is relatively small.

Viscosity is 250 centipoise (shear rate 38.40 sec)
If the temperature exceeds 100 to 50 centipoise (slip rate 38.4
They discovered the important finding that at 5ec-'*20°C), they almost spontaneously disperse in water, regardless of differences in surface tension and specific gravity.

This result shows that even with a suspension composition based on water having a specific gravity of more than 1, it is extremely difficult to directly handle the undiluted solution in flooded paddy fields.

The general composition of the herbicide suspension composition for rice fields according to the present invention is as follows.

Pyrazole compound represented by general formula (1) (referred to as C component) 10 to 40% (electronic) butachlor, or this and oxacyacin (referred to as B component)
3-30% (l weight) Surfactant (referred to as C component) 1-10% (l) Water-soluble polymer and protective colloid substance (referred to as D component) 0-1
0% (by weight) water and solvents (referred to as component C) The contents of the remaining components A and B are determined based on the herbicidal effect and cost of the formulation, but are preferably 10 to 30% by weight and 5 to 5% by weight, respectively.
It is 20% by weight.

Component C consists of a nonionic surfactant and an anionic surfactant, and is selected based on I (L B , chemical structure, surface tension, etc.) so as to sufficiently stabilize the dispersion of solid particles and the emulsion of liquid particles. Generally, both types of surfactants are often mixed to exhibit good effects.

Examples of anionic surfactants include alkylaryl sulfonates, lignin sulfonates, alkyl sulfates, dialkyl sulfosuccinates, naphthalene sulfonate formalin condensates, polyoxyethylene alkylphenyl ether sulfate salts, polyoxyethylene alkyl Phenyl ether phosphate salt, polyoxyethylene styryl (also habenzyl) phenyl (
Also, c. orun phenyl phenyl) ether sulfate salt, polyoxyethylenestyryl (or benzyl) phenyl (also ha ortho phenyl phenyl) ether sulfate salt, alkylnaphthalene sulfonate, etc., and nonionic surfactants include, for example. , polyoxyethylene alkyl allyl ether, polyoxyethylene alkyl ether, polyoxyethylene alkyl ester, polyoxyethylene castor oil, polyoxyethylene styryl (or benzyl) phenyl (also haorthophenylphenyl) ether, polyoxyethylene polyoxybrobylene There are many types of polymers such as block polymers, but they are not limited to these.

In addition, as the d component, a water-soluble polymer and a protective colloid substance are used for the purpose of further stabilizing the system in which the C component and the b component are suspended and emulsified with the C component and adjusting the viscosity. Ru.

Examples of water-soluble polymers or protective colloids include gum arabic, guar gum, sodium alginate, gelatin,
Casein, carboxymethylcellulose, xanthan gum, polyvinyl alcohol, sodium polyacrylate, polyvinylpyrrolidone, maleic anhydride-styrene copolymer, hydroxyethylcellulose, methylcellulose, and the like are used. These can be used alone or in combination of two or more.

The C component is mainly water, but if it is necessary to consider physical and chemical properties such as cold resistance, heat resistance, viscosity and specific gravity, methyl alcohol, ethyl alcohol, isopropyl alcohol, ethylene glycol, chrycerin,
Hydrophilic solvents such as ethylene glycol monomethyl ether, ethylene glycol ethyl ether, propylene glycol, or in some cases xylene, toluene,
One or more organic solvents selected from hydrophobic solvents such as kerosene and liquid paraffin may be added.

In addition to the above-mentioned components, the suspension herbicide composition for paddy fields according to the present invention may contain silicone-based, fatty acid-based, mineral oil-based, polyoxylic acid-based, Antifoaming agents such as ethylene polyoxypropylene block polymers, mineral carriers such as bentonite, kaolin, talc, and montmorillonite to prevent hard caking during long-term storage, synthetic silicates, petroleum resins, coumaron resins, ester gums, etc. There is no problem in adding other components such as resins, preservatives, etc.

The preparation of the suspension herbicidal composition for paddy fields of the present invention as a preparation is described in Japanese Patent Publications No. 46-20519, No. 58-24401, No. 58601-1987, No. 57-159703, No. 5B.
-124702, 58-162504, etc. can be used.

Since the pyrazole compound which is component C and the oxacyacin which is component b are solids, they are pulverized in advance using a dry grinder such as Jet-O-Miser, and then they are mixed with component C ~
A uniform herbicide suspension composition can be obtained by blending component e or other additives and stirring and mixing with a homogenizer. Further, in this case, the herbicide can be stabilized in the form of finer particles by wet grinding and mixing using a nocolloid mill such as a sand grinder, grain mill, or dyno mill without using a homogenizer. .

The solid herbicide thus suspended is stabilized as a suspended system with a particle size of 1 to 5 microns. However, when liquid butachlor is contained, it is stabilized as emulsified particles, so under conditions of vigorous crushing, stirring, and mixing such as in a high-speed homogenizer or the above-mentioned colloid mill, demulsification is likely to occur and separation may occur. In this case, a suspension composition of a solid herbicide is prepared in advance by the above method, and a mixture of a liquid herbicide and an emulsifier is gradually dropped into this composition using a low-speed homogenizer to emulsify it. In some cases, a suspension system of solid fine particles and an emulsion system of emulsified particles are stably mixed to form a composition. Therefore, since there is no standard method for preparing a suspension composition, a preparation method that takes advantage of the characteristics of components a to e may be used.

The pyrazole compound represented by the general formula (1) and butachlor, or R (14-type herbicide composition of oxacycin) finely adjusted by the above process, can be used directly during plowing work in flooded sewage paddy fields. It can be applied as a undiluted solution from a container.It is sprayed sufficiently uniformly for practical purposes, and shows a stable herbicidal effect on most weeds in paddy fields, in addition to broad-leaved weeds such as turmeric.For example: Use the undiluted solution in the container for 200 to 10
It is used by dispersing 00tLt/10a.

■ In the case of hand spraying, shake the bottle with your hand while walking just before or after puddling to spread the water. ■ In the case of mechanical spraying, attach a special spreader used for oxacyacin emulsions to a tractor, etc., and spread the water. Spray dropwise at the same time as work.

In the herbicide composition of the present invention, it was determined by Colby's method that there is a synergistic effect between component (4) and component (4) against common weeds in paddy fields such as field weed and staghorn snail. (See Test Example 1).

For example, S, R, Colby, @Calculat
ing Synergisticand Antago
nistic Re5ponses of Herbi
cide Com-binations”, Weeds
According to % 15.20-22 (1967), X=P? Damage for herbicide A when used in 710a, Y=qt Damage for herbicide B when used in 710a, E=P and qt/10 Herbicides A and B when used in a The expected damage in the case of , is expressed as -Y E=X+Y--.

And if the damage in the actual case is greater than the above calculated value, it is concluded that the effects of the combined drugs are more than additive and a synergistic effect exists.

Hereinafter, a detailed description will be given with reference to examples.

Compound A4 which was dry-pulverized in advance with a jet-o-mizer according to the example
0r, Oxacyacin 102, 0.1% aqueous mixture of xanthan gum and guar gum 95.4t1 Montmorillonite 0.6 F, petroleum resin (HiResin +120,
Toho Oil Resin ■) 2? , 6v of ethylene glycol and 6f of a mixture of 6 parts of polyoxyethylene styrylphenyl ether and 4 parts of dialkyl sulfosuccinate were placed in an 800 gobetsu cell of a sand grinder (manufactured by Igarashi Kikai Seisakusho), and 160 - of glass beads having a diameter of 2IIIll were added. 1.2200 rpm, 60 minutes, 25℃
Wet pulverization was performed as follows.

After pulverization, the contents were poured onto a 32-mesh sieve while deaerating to separate the glass beads, thereby obtaining 120 tons of a suspension composition. This suspension 82? into a universal type homogenizer (manufactured by Nippon Seiki), and stir slowly with a stirrer (6
0-100 rpm) Butachlor 10?
, kerosene 32, the above surfactant 5? A homogeneous mixture of 5
It was dripped in minutes.

Thereafter, stirring was continued for another 5 minutes at 150 to 200 rpm to obtain 100 tons of a suspension composition containing 20% of compound A, 10% of butachlor, and 5% of oxacyacin.

Example 2 Compound 'f that was dry-pulverized in advance with a jet-o-mizer
340f, 0 of a mixture of equal parts of xanthan gum and guar gum
．． 1% aqueous solution 105.4 f, montmorillonite 0.6
t, petroleum resin (...Iresin+120, Toho Oil Resin @>212 61° of ethylene glycol and 6f of a mixture of 6 parts of polyoxyethylene styrylphenyl ether and 4 parts of dialkyl sulfosuccinate were charged into an 800d vessel of a sand grinder, and the diameter 2- Add 160d of glass beads, 2200 rpm, 60
Wet milling was carried out at 25° C. or lower for 1 minute. After pulverization, the contents were poured onto a 32-mesh sieve while deaerating to separate the glass beads, yielding 120 tons of suspension. This suspension Sat was placed in a universal type homogenizer, and while stirring slowly (60 to 100 rpm) with a stirrer, 122% butachlor and 31% kerosene were added. A homogeneous mixture of the above surfactant 5f was added dropwise over 5 minutes. After that, 15 minutes for another 5 minutes.
Stirring was continued at 0 to 200 rpm to obtain 100 tons of a suspension composition containing 20% of compound B and 12% of butachlor.

Example 1 In the same manner as in Example 2, except that Compound B was replaced with Compound C, which had been dry-pulverized in advance with a jet-o-mizer,
A suspension composition 100f containing 20% of Compound C and 12% of butachlor was obtained.

Comparative Example In Example 1, the 0.1% aqueous solution of a mixture of equal amounts of xanthan gum and guar gum was changed to an i, o% aqueous solution of a mixture of equal amounts of xanthan gum and guar gum. A suspension composition 100f containing % was obtained.

Comparative Example 2 Compound B 20%, butachlor A suspension composition 100f containing 12% was obtained.

The suspension compositions obtained in the above Examples and Comparative Examples were evaluated by the following test method.

(1) Specific gravity (20/4°C) JIS-0011 (pycnometer method) (2) 1 Surface tension (25°C) JIS-3362
(Destay method) (3), Viscosity (20℃) Rotation speed 10 r, p,
m.

Shear rate: 38.408 eC - E-type viscometer (manufactured by Tokyo Keiki ■) (4) Natural dispersion test A Petri dish with a diameter of 27 cm and a depth of 15 cm was filled with 25°C tap water to a depth of 10 cW1. After standing, the suspension herbicide composition 1d obtained on each side from the height 103 above the water surface in the center of the Petri dish was gently dropped with a pipette to check its spreadability on the water surface and its susceptibility in water. Natural dispersion was observed.

Rating: O: Partially spread on the water surface and almost naturally dispersed in the water.

△: Does not spread on the water surface and partially naturally disperses in the water.

×: Hardly spread or naturally disperse on the water surface or in water.

(5) Ill turbidity stability test The suspended herbicide composition on each side was placed in a 50-meter stirrer with a stopper, and the stopper was closed.
The sample was stored for one month, and the presence or absence of the aqueous layer separation layer (1) and hard caking, as well as its restorability, were observed.

The test results are shown in Table-1.

(Left below) Test example 1 (soil 1 mixing treatment) 1 section 10W? Using a rice field partitioned into (2 m x 5 yP+), the test was conducted in the following manner, with each test plot being repeated three times.

To ensure that weeds would grow uniformly, we sowed a certain amount of seeds of Japanese grasshopper, Kikashigusa, Konagi, and Firefly, which germinate well, one day after weeding, and furthermore, we embedded 20 tubers of Urikawa and Mizugayatsu in each plot. Furthermore, after one day, it was submerged in water at a depth of 3 to 4 anm, and the drugs prepared in each example and comparative example were submerged in water at a depth of 7.5 m (
750d/10a) and immediately stirred with a rake from the surface layer to a depth of about 5cm. Two days after spraying the chemical, 2.5 leaves of rice were transplanted. Thereafter, it was flooded to a depth of 3 to 4 c1tg and maintained until the survey date.

The herbicidal effect was determined by pulling out surviving weeds 30 days after the chemical treatment, measuring their dry weight, comparing with the untreated area, and performing a test using Colby's method. Chemical damage to rice was also observed at that time. The results were as shown in Table 2 (
(Displayed as the average of the three wards).

Test example 2 (turbid water treatment) A rice field treated with weeds in the same manner as test example 1 was prepared, and
After a few days, it will be flooded to a depth of 3 to 4 cm, and with a rake it will be 51 cm from the surface layer by ±1.
Stir to a certain depth. Immediately thereafter, 7.5v (7so*/loa
) was dispersed. 2 days after spraying the chemical.
Rice was transplanted at the 5-leaf stage. Thereafter, the area was flooded to a depth of 3 to 43 mm and maintained until the day of the survey. The herbicidal effect was investigated in the same manner as Test Example 1. The results were as shown in Figure 3.

(Left below) Test Example 3 (Fresh water treatment) A rice field treated with weeds in the same manner as Test Example 1 was prepared, and
After 3 to 4 days, flood the soil to 5cr from the surface layer with a rake.
The mixture was stirred to a depth of about n. Approximately 6 hours later, when the rice water became clear, 7.5 d of the drugs prepared in each Example and Comparative Example were added.
(equivalent to 750 yd 710 a), evenly distributed. Two days after the chemical application, rice plants at the 2.5 leaf stage were transplanted. Thereafter, the water was flooded to a depth of 3 to 4 α and maintained until the day of the survey.

The herbicidal effect was investigated in the same manner as Test Example 1. The results are shown in the table-
It was as shown in 4.

(Leaving space below) Test Example 4 (Post-transplant treatment using water mouth application) A paddy field treated with weeds in the same manner as Test Example 1 was prepared, and
After a day, flood the soil to a depth of 3 to 4 cm and use a rake to reach 5 cm from the soil surface.
! The mixture was stirred to a depth of about n. After keeping the water submerged for 2 days, rice at the 2.5 leaf stage was transplanted.

7. Three days after transplantation, the drugs formulated in each Example and Comparative Example were administered.
5 d (equivalent to 750 d/10 a) was applied from the water outlet of each plot to the running water so that it was evenly distributed. From now on 3
The water was flooded to a depth of ~4 m and maintained until the survey date. The herbicidal effect was investigated in the same manner as Test Example 1.

The results were as shown in Table-5.

(Margin below)

Claims (1)

[Claims] (1) General formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼... (I) (In the formula, R is a hydrogen atom or a methyl group, Z is a p-toluenesulfonyl group, a phenacyl group, or a p-toluenesulfonyl group, a phenacyl group, or a - methylphenacyl group) and (B) α-chloro-2',6'-diethyl-N-(n-
(ptoxymethyl)acetanilide, or its combination with 3-(2
,4-dichloro-5-isopropoxyphenyl)-5-
tert-butyl-1,3,4-oxadiazole-2
Contains -(3H)-one as an active ingredient and has a viscosity of 250
~30 centipoise (shear rate 38.40 sec^-^
1.20°C).